The following relates generally to wireless communication, and more specifically to multiplexing uplink transmissions with transmit diversity with single carrier waveform.
Wireless communications systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. These systems may be capable of supporting communication with multiple users by sharing the available system resources (e.g., time, frequency, and power). Examples of such multiple-access systems include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, and orthogonal frequency division multiple access (OFDMA) systems, (e.g., a Long Term Evolution (LTE) system, or a New Radio (NR) system). A wireless multiple-access communications system may include a number of base stations or access network nodes, each simultaneously supporting communication for multiple communication devices, that may be otherwise known as user equipment (UE).
In a LTE or LTE-Advanced (LTE-A) network, a set of one or more base stations may define an eNodeB (eNB). In other examples (e.g., in a next generation new radio (NR) or 5G network), a wireless multiple access communication system may include a number of smart radio heads (RHs) in communication with a number of access node controllers (ANCs), where a set of one or more RHs, in communication with an ANC, defines a base station (e.g., an eNB or gNB). A base station may communicate with a set of UEs on downlink (DL) channels (e.g., for transmissions from a base station to a UE) and uplink (UL) channels (e.g., for transmissions from a UE to a base station).
A base station in some LTE or NR deployments may transmit downlink transmissions to one or more UEs, and the one or more UEs may transmit uplink transmissions back to the base station. In some cases, downlink transmissions may be transmitted using OFDM transmissions in which multiple carriers are used to transmit concurrent OFDM resource elements (REs), and uplink transmissions may be transmitted using a single-carrier waveform such as single-carrier frequency division multiplexing (SC-FDM) or discrete-Fourier-transform (DFT) spread OFDM (DFT-s-OFDM) transmissions. In some cases it may be desirable for multiple UEs to concurrently transmit uplink communications back to the base station. Additionally, in some cases a UE may use multiple transmit antennas for uplink transmissions to provide transmit diversity.